/* wf_exp.c -- float version of w_exp.c.
 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
 */

/*
 * ====================================================
 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
 *
 * Developed at SunPro, a Sun Microsystems, Inc. business.
 * Permission to use, copy, modify, and distribute this
 * software is freely granted, provided that this notice
 * is preserved.
 * ====================================================
 */

/*
 * wrapper expf(x)
 */

#include "fdlibm.h"
#include <errno.h>

#ifdef __STDC__
static const float
#else
static float
#endif
o_threshold=  8.8721679688e+01,  /* 0x42b17180 */
u_threshold= -1.0397208405e+02;  /* 0xc2cff1b5 */

#ifdef __STDC__
    float expf(float x)     /* wrapper expf */
#else
    float expf(x)           /* wrapper expf */
    float x;
#endif
{
#ifdef _IEEE_LIBM
    return __ieee754_expf(x);
#else
    float z;
    struct exception exc;
    z = __ieee754_expf(x);
    if(_LIB_VERSION == _IEEE_) return z;
    if(finitef(x)) {
        if(x>o_threshold) {
        /* expf(finite) overflow */
#ifndef HUGE_VAL
#define HUGE_VAL inf
            double inf = 0.0;

            SET_HIGH_WORD(inf,0x7ff00000);  /* set inf to infinite */
#endif
        exc.type = OVERFLOW;
        exc.name = "expf";
        exc.err = 0;
        exc.arg1 = exc.arg2 = (double)x;
        if (_LIB_VERSION == _SVID_)
          exc.retval = HUGE;
        else
          exc.retval = HUGE_VAL;
        if (_LIB_VERSION == _POSIX_)
          Djy_SaveLastError(ERANGE);
        else if (!matherr(&exc)) {
            Djy_SaveLastError(ERANGE);
        }
            if (exc.err != 0)
               Djy_SaveLastError(exc.err);
            return exc.retval;
        } else if(x<u_threshold) {
        /* expf(finite) underflow */
        exc.type = UNDERFLOW;
        exc.name = "expf";
        exc.err = 0;
        exc.arg1 = exc.arg2 = (double)x;
        exc.retval = 0.0;
        if (_LIB_VERSION == _POSIX_)
          Djy_SaveLastError(ERANGE);
        else if (!matherr(&exc)) {
            Djy_SaveLastError(ERANGE);
        }
            if (exc.err != 0)
               Djy_SaveLastError(exc.err);
            return exc.retval;
        }
    }
    return z;
#endif
}

#ifdef _DOUBLE_IS_32BITS

#ifdef __STDC__
    double exp(double x)
#else
    double exp(x)
    double x;
#endif
{
    return (double) expf((float) x);
}

#endif /* defined(_DOUBLE_IS_32BITS) */
